Please take a look at a sample research project. The question was how much difference it makes if a volume profile is calculated using tick data or using the volume gathered from 1 minute bars. It’s clear that using volume information from one minute bars will be less accurate, but will the difference be too great to base trading decisions on those volume profiles? To answer this question we compared the difference in price for the E-Mini S&P 500 Volume Point of Control (VPOC) over a sample size of 1088 trading days, when calculated from tick data and from minute data.As you can see in this graph, on roughly 30% of the days there is no difference in the VPOC at all. The first standard deviation (meaning the area where 68.2% of the values are found) is only four ticks wide, meaning the difference is only two ticks or less 68.2 % of the days.
There are a couple of extreme outliers and these are to be found on days with showing a double distribution or several distributions. If the highest volume within those distributions is close to each other, it becomes more likely for the VPOC on the minute charts to be within the different distribution compared to the VPOC calculated from the one tick chart.